Fabric



United States Patent 3,421,827 FABRIC Kermit S. La Fleur, Clemson, S.C., assignor to Deering Milliken Research Corporation, Spartanburg, S.C., a corporation of Delaware No Drawing. Filed Dec. 11, 1962, Ser. No. 243,748 US. Cl. 8-14 8 Claims Int. Cl. D06p 7/00 This invention relates to the preparation of an embossed fabric and more specifically to the preparation of an embossed keratinous fiber containing fabric.

Durable relief designs are commonly impressed on thermoplastic fiber containing fabrics by means of heat and pressure, and on non-thermoplastic fiber containing fabrics by means of setting the relief design with a thermosetting or thermoplastic resin binder. As the use of a binding medium effects the hand and drape of a fabric, it is highly desirable that an embossed effect be produced without resorting to a. binder. The embossed effect is desirable because of its functional ability to provide superior thermoinsulation. The superior thermoinsulating qualities arise from the fact that air is trapped in the depressions caused by the embossing, trapped air being a well-known thermoinsulant. An embossed effect, in addition to its functional aspects, is also desirable from a decorative viewpoint. Where the decorative aspects are a major consideration, it is frequently desired that a differential dyeing effect be obtained in the embossed areas.

It is therefore an object of this invention to provide a method for the preparation of a keratinous fiber containing fabric of good hand and drape having a durable embossed effect.

It is a further object of this invention to provide a method for the preparation of a keratinous fiber containing fabric of good hand and drape having a durable embossed effect and having a differential dyeing effect, the degree of the differential being determined by the extent of the embossing and by the selection of the dye bath.

In accordance with this invention, it has now been discovered that a keratinous fiber containing fabric may be durably embossed by treating the fabric with a reducing agent capable of splitting the characteristic cystine linkage of keratinous fibers, placing the wet treated fabric in a mold and then setting the molded fabric by the application of heat. The fabric employed may be a fabric consisting entirely of keratinous fibers or may be a fabric containing less than 100% but more than 30% of keratinous fibers with the remainder of the blend being either manmade or naturally-occurring non-keratinous fibers. Specific keratinous fibers which are suitable for purposes of this invention are fibers such as, for instance, sheepwool, lambwool, mohair, camelhair, alpaca, cashmere, vicuna, llama, angora wool and the like.

The fibers employed need not be quality grade fibers or fibers of the type which are reuseable for commercial grade fabrics but may be waste fibers or varying proportions of waste and quality fibers. The term waste fibers as used herein is meant to include those fiber residues which are found in textile mill operations such as, for instance, fiber sweeps from carding, combing, quilling, spinnig, head ends and drawing operations. While fabrics prepared from waste fibers are normally lacking in strength, it has been foundthat the embossing treatment of this invention imparts increased strength to a keratinous fiber containing fabric consisting wholly or partially of waste fibers. The low price of waste fibers makes the use of these fibers a most attractive application of 'the embossing process of this invention.

Any reducing agent capable of rupturing the desired level of the disulfide linkages is suitable for use in accordance with this invention. Among the suitable reducing 3,421,827 Patented Jan. 14, 1969 ice agents there are included lower alkanolamine sulfites, such as monoethanolamine sulfite and isopropanolamine sulfite, and others containing up to about 8 carbon atoms in the alkyl chain, such as n-propanolamine sulfite, n-butanolamine sulfite, dimethylbutanolamine sulfite, dimethylhexanolamine sulfite and the like; metallic formaldehyde sulfoxylates, such as zinc formaldehyde sulfoxylate, the alkali metal sulfoxylates, such as sodium formaldehyde sulfoxylate the alkali metal borohydrides, such as sodium borohydride, potassium borohydride and sodium potassium borohydride; alkali metal sulfites, such as sodium or potassium bisulfite, sulfite, metabisulfite, or hydrosulfite; ammonium bisulfite, sodium sulfide, sodium hydrosulfide, sodium hypophosphite; sodium thiosulfate, sodium dithionate; titanous chloride; sulfurous acid; mercaptan acids, such as thioglycollic acid and its water-soluble salts, such as sodium, potassium or ammonium thioglycolate; mercaptans, such as hydrogen sulfide, and sodium or potassium hydrosulfide; alkyl mercaptans, such as butyl or ethyl mercaptans and mercaptan glycols, such as fi-mercapto ethanol; and mixtures of these reducing agents.

Beneficial results are often obtained if the reducing agent is employed in conjunction with a swelling agent or a low molecular weight polyhydroxy compound." Urea constitutes the most readily available and desirable swelling agent, although any other material which will swell wool fibers in an aqueous medium is suitable. For example, guanadine compounds such as the hydrochloride; formamide, N,N-dimethylformamide, acetamide, thiourea, phenol, lithium salts, such as chloride, bromide, and iodide and the like are similarly useful.

By the term low molecular weight polyhydroxy compound is meant a compound containing more than one hydroxy group and having a molecular weight no greater than about 4000. Of these compounds, the most readily available and desirable compound, from the standpoint of ease of application, comprises ethylene glycol. A particularly preferred group of glycols includes the polyfunctional glycols having terminal hydroxyl groups separated by 2 to 10 methylene groups, including, of course, the preferred ethylene glycol as well as trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, and decamethylene glycol, or such glycols as 1,2-propylene glycol, dipropylene glycol, 1,3- butylene glycol, diethylene glycol, polyethylene glycol or the like.

Polyfunctional compounds containing more than 2 hydroxyl groups include the polyfunctional alcohol glycerols such as glycerine and diethylglycerol as well as trimethylol ethane, trimethylol butane, tris-hydroxymethyl-amino methane and others. Gylcol ethers, such as the watersoluble or dispersible polyethylene glycols or polypropylene glycols having molecular weights no greater than about 4000 also provide satisfactory results when utilized in accordance with this invention.

The reducing agent with or without the swelling agent or polyhydroxy compound may be applied to the fabric in any desired amount depending upon the degree of reducing desired. In general, optimum results are obtained when aqueous solutions containing from about 0.01 to about 20% by weight and most preferably from 1 to about 10% by weight of the reducing agent is applied to the yarn. The swelling agent or polyhydroxy compound if employed may be applied to the yarn by addition to the aqueous solution of reducing agent of amounts of from about 3 to about 50% and most preferably from about 5 to about 20% by Weight. Higher concentrations may be utilized where the yarn is to be exposed to the treating medium for only a short time or where the method of applying the reagents necessitates, e.g., when the reagents are applied by techniques other than by immersion in an anqueous medium containing the reagents.

The reducing agent which splits the cystine linkage of the keratinous fibers does not produce a permanent split. The split linkages are easily reoxidized by operations such as, for instance, atmospheric exposure to reform the disulfide bonds. While the keratinous fibers remain substantially unchanged chemically by the reduction and oxidation operation, a physical reformation of the cystine linkages take place probably with some changes in hydrogen bonding which will under proper conditions produce a reformed fiber. The reformation of the fiber gives the individual keratinous fibers of this invention their ability to conform to a molded configuration.

The process can be carried out by immersing the keratinous fiber containing fabric in an aqueous solution of a reducing agent. The reducing agent is present in the soultion in quantities of from 1% by weight to the solubility limit of the reducing agent. The pH of the reducing agent solution is maintained in the range of from about 5 to about 9. The pH is preferably maintained at about 5 as there is less likelihood of damaging woolat a lower pH. The fabric is then squeezed to 100% wet pick-up and placed in a mold. The mold is then subjected to heat and pressure, the pressure varying from about 0 p.s.i. to about 600 p.s.i. The molding temperatures may vary from about 200 F. to about 600 F., the molding temperature being dependent upon molding time limits. In general, the fabric is retained in the mold for periods of from about 0.2 minute to about 4.0 minutes, the longer time periods being necessary Where lower temperatures are employed. Keratinous fiber containing fabrics treated in the foregoing manner produced designs having an attractive appearance which were durable to aging. The keratinous fiber containing fabrics treated in the manner set forth in this invention have a high degree of resistance to dry cleaning operations. Where, however, an embossed keratinous fiber containing fabric which is resistant to washing or hot water treatment is desired, it is necessary that the keratinous fiber containing fabric also contain amounts of thermoplastic fibers such as, for instance, fibers prepared from polyamides, polyesters, acrylonitrile polymers and copolymers and cellulose esters and the like. In order to obtain improved results from the presence of thermoplastic fibers, the thermoplastic fiber should be present in quantities of not less than and preferably should be present in the range of from 70% to 30%.

Where an ornamental fabric is of prime importance, the embossed keratinous fiber containing fabric prepared according to the method set forth herein may also be subjected to dyeing operations. While any of the dyeing operations commonly employed in the coloration of wool fabrics may be employed, it has been found that an unexpected result is obtained when an acidic dye treatment of the melange type is employed. The term melange as employed herein is meant to include a two-tone effect, a tone-in-tone effect, and a multi-color effect.

It is known that the dyeing behavior of acidic dyes depends on molecular size and on the number and strength of acidic groups and other polar groups present on the molecules. The acid dyes may possess carboxyl groups, sulfonic acid groups or both. Acidic dyes color wool by formation of electrovalent bonds with basic amino groups. The variation in wool coloration effected by acid dyes may be increased by selecting dye baths which contain acid dyes having at least two sulfonate groups and optionally other dyes which are free of sulfonate groups or which contain only one sulfonate group.

The variation in wool coloration effected by acid dye or dyes may also be increased by adding to the acid dye bath a condensation product of an aldehyde with an aromatic sulfonic acid containing at least two sulfonate groups.

It is known that dyes attempting to penetrate a protenic fiber encounter considerable resistance at the surface of the fiber, the resistance appearing to be principally from the cuticle. This retardation is relatively slight when acid dyes of low molecular weight are used but much greater with acid dyes of high molecular weight. The variations in resistance to dyeing which occur at the surface of a proteinic fiber afford one theory for the melange effect which may be obtained with certain dye baths when applied to proteinic fibers. The dyeing resistance which is encountered by high molecular weight acid dyes is increased when an aldehyde condensation agent is present. The aldehyde condensation agent appears to occupy areas of intermediate accessability thereby further restricting the area of entry of high molecular weight acid dyes.

It has now been discovered that when a keratinous fiber containing fabric is embossed according to the method of this invention that the keratinous fibers in the embossed portions of the fabric are modified in a manner which makes them more receptive to dyeing and more specifically more receptive to the differential type of dyeing obtained with melange type dyeing operations. While an enhanced melange effect may be obtained by dyeing the embossed fabric of this invention with dye baths containing acid dyes having more than three sulfonate groups and optionally other dyes which are free from or which contain only one sulfonate group, the preferred dye bath is a dye bath containing an aldehyde sulfonic acid condensation product such as set forth in U.S. Patent No. 2,999,731. The result of the use of the patented process with the embossed fabrics of this invention is that the melange dyeing effect serves to highlight the embossed areas of the fabric.

The modification of the fibers which takes place at the embossed portions of the fabric appears to be greater swellability and a removal or disruption of the cuticle of the proteinic fiber. This modification of the fiber increases the rate of dye absorption and will provide increased contrast in the embossed areas when the embossed fabric is subjected to melange type dyeing operations.

In accordance with this invention, an embossed keratinous fiber containing fabric may be treated with an aqueous solution or paste containing:

(a) A condensation product of an aldehyde, particularly formaldehyde and an armoic sulfonic acid or a water-soluble salt of such condensation product;

(b) A water-soluble organic aliphatic acid which is non-injurious to wool, preferably acetic acid or formic acid;

(c) At least one dyestutf which will dye wool and which contains at least two sulfonic acid groups in the molecule;

The said aqueous solutions or paste having an initial pH of between 2.8 and 4.9 preferably between 3.4 and 4.5.

Examples of the component (a) are:

Condensation products of the general formula where R is an aryl radical which contains at least one sulfonic acid group and may contain one or more amino, hydIoXyl, nitro, chlorine or thiol substituents and n is an integer, preferably 1 or 2.

Specific examples of the compounds are dinaphthylmethane disulfonic acids, diphenylmethane disulfonic acids, dicresylmethane disulfonic acids, sodium dicresylmethane disulfonates, dixylylmethane disulfonic acids, diaminonaphthylmethane disulfonic acids, dichloronaphthylmethane disulfonic acids, dinitronaphthylmethane disulfonic acids and dithionaphthylmethane disulfonic acids.

- The dyestufls employed in conjunction with the aldehyde-sulfonic acid condensation product may be selected from the classes of acid, direct, acid pre-metalized, chrome, and flourescent dystuffs or indeed any dyestufi which will dye wool provided that it contains at least two sulfonic acid groups in the molecule. It should be understood that other dyes containing one sul-fonate group or no sulfonate groups may optionally be persent where a multi-tone or a tone-in-in tone effect is desired.

Various embodiments of this invention will become apparent from the following specific .examples. The examples, however, are given for purposes of illustration and should not be considered as limiting the spirit or scope of this invention.

EXAMPLE I An all-wool fabric containing 25% by weight of waste wool fibers is placed in a 1% by weight aqueous solution of sodium sulfite having a pH of '9. The temperature of the sodium bisulfite solution is maintained at 70 F. The woolen fabric is then squeezed to a 100% wet pick-up and placed in a mold having a stainless steel template with diamond shaped openings. The mold is then subjected to pressures of 500 p.s.i. and temperatures of 300 F. for a period of three minutes. The finished fabric is a fabric having an attractive design pattern and having a high degree of durability to aging.

EXAMPLE II .A worsted fabric comprising 75% wool and 25%Orlon is immersed in a 1% aqueous solution of sodium bisulfite.-

The sodium bisulfite solution is controlled at a temperature of about 70 F. and a pH of about 5. The fabric is squeezed to a 100% wet pick-up and placed in a mold having a template of stainless steel with diamond shaped openings. The mold is subjected to pressures of 500 p.s.i. and a temperature of about 500 F. for a period of 0.5 minute. The resultant product is a fabric having an attractive diamond shaped pattern and having a high degree of durability to aging and a high degree of resistance to embossed design loss in hot water.

EXAMPLE III A fabric consisting of 50% by weight wool and 50% by weight Orlon (polyester fiber prepared by E. I. du Pont de Nemours & Company) is placed in a 1% by weight aqueous solution of n-propanolamine sulfite and 3% by weight ethylene glycol maintained at a pH of 5. The temperature of the reducing agent solution is held at about 70 F. The wool/Orlon blend fabric is squeezed to a 100% wet pick-up and placed in a-mold having a stainless steel template with diamond shaped openings. The mold is then subjected to pressures of 100 p.s.i. and temperatures of 300 F. for a period of three minutes. The finished fabric is a fabric having an attractive design pattern and having a high degree of durability to aging and laundering.

EXAMPLE IV A worsted fabric is immersed in a 1% solution of sodium hydrosulfite. The solution is maintained at a temperature of about 70 F. and at a pH of about 8. The wool fabric is then squeezed to a 100% wet pick-up. The fabric is then placed in a mold having a stainless steel template with diamond shaped openings. The mold is subjected to pressures of about 500 p.s.i. and temperatures of about 400 F. for a period of about 1.5 minutes. The wool fabric which has an embossed diamond shaped design is then placed in a dye bath consisting of water and the following components whose percentages are given as percent by weight based on the dry fabric weight. The components are 5% Glaubers salt, 2% naphthalene-formaldehyde sulfonic acid condensation product, 1% Pluronic F-6-8 (nonionic surfactant marketed by Wyandotte Chemicals Corporation), 0.25% Alphazurine A (Color Index No. 42090). The embossed fabric is placed in the dye bath and the dye bath is then brought to a boil and maintained at boiling temperatures for a period of 60 minutes. The dyed product is an embossed wool fabric wherein the embossed areas have heavy concentration of blue dye while the remainder of the 'fabric is either white or contains varying degrees of blue dye."

6 EXAMPLE v A wool fabric is embossed in the manner set forth in Example HI. A dye bath is then prepared consisting of water and the following components whose percentages are given in percent by Weight based on the dry fabric weight. The components are 5% Glaubers salt, 2% naphthalene-formaldehyde sulfonic acid condensation product, 3% acetic acid, 1% Pluronic F-68 (nonionic surfactant marketed by Wyandotte Chemicals Corporation), 0.5% Sulfon Acid Blue RA (Color Index No. 13390), and 1% Pontacyl Light Yellow 3G (Color Index No. 18820). The embossed wool fabric is placed in the dye bath and the dye bath is then brought to a boil and maintained at boiling temperatures for a period of about one hour. The dyed product is an embossed wool fabric wherein the embossed area contains heavy concentrations of blue dye. The remainder of the fabric has a varying two-tone effect of blue and yellow dye.

EXAMPLE VI A wool fabric is embossed in the manner set forth in Example III. A dye bath is then prepared from water and the following components whose percentages are given in percent by weight pick-up based on the dry fabric weight. The components are 5% Glaubers salt, 1% Pluronic F- 68 (nonionic surfactant marketed by Wyandotte Chemicals Corporation), 2% acetic acid and 0.25% Alphazurine A (Color Index No. 42090). The embossed Wool fabric is placed in the dye bath and the dye bath is then brought to a boil and maintained at boiling temperatures for a period of about 60 minutes. The dyed product is an embossed wool fabric wherein the embossed areas contain more pronounced quantities of blue dye, the remainder of the fabric being white or containing varying degrees of blue dye. The concentration of color in the embossed areas of the fabric of this example is not as noticeable as the concentration of color in the embossed areas of the fabric of Example IV.

EXAMPLE VII A worsted fabric is embossed according to the method set forth in Example IV. A Wool dye bath is then prepared from water and the following components whose percentages are given in percent by Weight based on the dry 'fabric'weight. The components are 5% Glaubers salt, 1% Pluronic F-68 (nonionic surfactant marketed by Wyandotte Chemicals Corporation), 3% acetic acid, 0.5% Sulfon Acid Blue RA (Color Index No. 13390), and 1% Pontacyl Light Yellow 36 (Color Index No. 18820). The embossed fabric is placed in the dye bath and the dye bath is then brought to a boil and maintained at boiling temperatures for a period of about one hour. The dyed product is an embossed wool fabric wherein the embossed areas contain greater concentrations of blue dye. The remainder of the fabric has a varying two-tone effect of yellow and blue dye. The dyeing differential obtained in the embossed area of the fabric of this example is not so pronounced as that obtained in the fabric Example V.

What is claimed is:

1. A method for the preparation of an embossed keratinous fiber containing fabric having a melange dyed effect with heavier concentration of dye in the embossed areas comprising immersing said keratinous fiber containing fabric in an aqueous solution of a reducing agent, placing thereducing agent treated fabric in a mold and subjecting said fabric to heat and pressure and then subjecting the resultant embossed keratinous fiber containing fabric to a melange type dye bath. I

2. The method of claim 1 wherein said keratinous fiber containing fabric is an all-keratinous fiber containing fabric.

3. The method of claim 1 wherein said keratinous fiber containing fabric is a fabric consisting of a blend of keratinous fibers and thermoplastic fibers.

4. A method for the preparation of an embossed keratinous fiber containing fabric having a melange dyed effect with heavier concentration of dye in the embossed areas comprising immersing said keratinous fiber containing fabric in an aqueous solution of a reducing agent, placing the reducing agent treated fabric in a mold and subjecting said mold to heat and pressure and then subjecting the resultant embossed keratinous fiber containing fabric to a dye bath comprising, at least one acid dye having more than two sulfonate groups.

5. The method of claim 4 wherein said dye bath comprises at least one acid dye having more than two sulfonate groups and at least one dye which contains not more than one sulfonate group.

6. A method for the preparation of an embossed keratinous fiber containing fabric having a melange dyed effect with heavier concentration of dye in the embossed areas comprising immersing said keratinous fiber containing fabric in an aqueous solution of a reducing agent, placing the reducing agent treated fabric in a mold and subjecting said fabric to heat and pressure and then subjecting the resultant embossed keratinous fiber containing fabric to a dye bath comprising a condensation product of an aldehyde With an aromatic sulfonic acid containing at least three sulfonate groups and at least one acid dye containing at least two sulfonate groups.

7. The method of claim 6 wherein said dye bath comprises a condensation product of an aldehyde with an aromatic sulfonic acid containing at least three sulfonate groups, at least one acid dye containing at least two sulfonate groups and at least one dye which contains not more than one sulfonate group.

8.. An embossed melange dyed keratinous fiber con taining fabric prepared by the process of claim 1.

References Cited UNITED STATES PATENTS 1,557,461 10/1925 Lauten 814 3,077,655 2/1963 Runton 8-128 X 3,059,990 10/1962 Koenig et al 8--128 FOREIGN PATENTS 216,612 11/ 1957 Australia.

5/1957 Great Britain. 6/1960 Great Britain.

OTHER REFERENCES Speakman et al.: Journal of the Textile Institute, T627-628 (1958).

Speak-man: Journal of the Textile Institute, vol. 50, 173 1959 NORMAN G. TORCHIN, Primary Examiner.

J. CANNON, Assistant Examiner.

US. Cl. X.R. 8-54, 128 

1. A METHOD FOR THE PREPARATION OF AN EMBOSSED KERATINOUS FIBER CONTAINING FABRIC HAVING A MELANGE DYED EFFECT WITH HEAVIER CONCENTRATION OF DYE IN THE EMBOSSED AREAS COMPRISING IMMERSING AND KERATINOUS FIBER CONTAINING FABRIC IN AN AQUEOUS SOLUTION OF A REDUCING AGENT, PLACING THE REDUCING AGENT TREATED FABRIC IN A MOLD AND SUBJECTING SAID FABRIC TO HEAT AND PRESSURE AND THEN SUBJECTING THE RESULTANT EMBOSSED KERATINOUS FIBER CONTAINING FABRIC TO A MELANGE TYPE DYE BATH. 